DIAGNOSIS; THE WAY WE LIVE NOW: THE STREP THROAT THAT WASN'T: 9-14-08

By LISA SANDERS, M.D.

Published: September 14, 2008

1.Symptoms

''I -- can't -- breathe,'' the boy gasped. There was panic in his voice and face. He moved restlessly in his hospital bed, tugging at the clear plastic mask covering his nose and mouth. An alarm sounded distantly, alerting the nurses to the boy's distress in the pediatric intensive-care unit of the Cardinal Glennon Children's Medical Center in St. Louis. Before the nurses could respond, the boy's mother replaced the oxygen mask, stroking his face and murmuring reassurances as if he were 7 years old rather than 17.

Dr. Jeremy Garrett, an associate professor of pediatrics at St. Louis University School of Medicine, was worried about the boy. When Garrett first saw him, early that morning, he wondered what this robust man-child was doing in the ward reserved for the very sickest children. At that point, the patient had a fever but otherwise looked well.

Since then, the boy's symptoms had become significantly worse. The amount of oxygen in his blood was terrifyingly low despite getting 100 percent oxygen through the mask covering the lower half of his face. (The air we typically breathe contains about 20 percent oxygen.) And he was breathing rapidly, at nearly three times the normal rate. He had episodes of shuddering, body-wrenching chills -- where blanket after blanket couldn't warm him -- followed by fevers as high as 105 degrees.

In reviewing the chart, Garrett saw that the boy had been well until six days earlier, when he awoke with a fever and sore throat. He saw his family doctor the next day, who diagnosed a strep throat and started the boy on a five-day course of azithromycin -- an antibiotic widely used in part because it is convenient, needing to be taken only once each day. No strep test was done -- probably, Garrett figured, because the diagnosis seemed obvious. Despite the antibiotics, the boy continued to spike fevers up to 102 degrees, and the pain and swelling had migrated from his throat to the right side of his neck.

The boy's parents took him to the hospital because something about the way he looked scared them. He wasn't confused, but his responses were slow and strangely deliberate.

2. Investigation

When the family arrived at the emergency department, the boy had a fever and was breathing rapidly. The right side of his neck was tender and slightly red. The rest of the exam was normal. A chest X-ray revealed a few small patches of white in both lungs -- areas that would normally show up as black. Blood tests indicated that the blood cells that fight infection were quite elevated. And most of those cells were immature forms, called bands, suggesting that many of the veteran fighter cells had already been destroyed by a serious infection.

The emergency-department doctors started the boy on two antibiotics for what they thought was probably a pneumonia. Although the patient didn't have much of a cough and the findings on the X-ray didn't seem significant enough to cause a week of fever and shortness of breath, the doctors couldn't find any other abnormality. After the boy's fever went up and his oxygen level went down 12 hours after his admission, Garrett added a third antibiotic and began to wonder what else this might be.

Garrett's concern was that a hidden infection was now seeding his lungs with flecks of infected tissue. That would explain the intermittent fever and patchy image on the chest X-ray. Was this endocarditis, an infection of the valves of the heart? Endocarditis can cause persistent fervers and desseminate infected tissue throughout the body. What about Lemierre's syndrome -- a rare infection caused by bacteria that usually start in the tonsils but then invade the vessels of the neck, causing the blood to clot there and peppering the lungs with infected bits? The boy had complained of pain just below the right side of his jaw. Or was this an abscess hidden in the deep recesses of his tonsils? Such a walled-off pocket of infection might not respond to even the most powerful antibiotics.

As Garrett pored over the chart, he noted that each of these possibilities had already been considered. The boy had been seen by an cardiologist, ear, nose and throat specialist and an infectious-disease expert. An echocardiogram -- an ultrasound of the heart -- showed no sign of infection of his valves. He had an ultrasound of his neck as well to look for an abscess or clot in the vessels there. When none were found, doctors ruled out tonsillar abscess and Lemierre's. Blood cultures still had not given the doctors any clue what the infectious agent might be.

Overnight the boy's breathing continued to worsen. By early the next morning, he could no longer supply his body with the oxygen he needed, and he was put on a ventilator. Simply keeping the boy alive became the doctor's sole focus.

After three difficult days, the team finally was given a clue -- though it was nearly missed. Garrett saw the resident looking through some papers in the boy's chart. What's that? he recalls asking. The blood cultures finally grew strange bacteria, the resident responded, but it was probably just contaminant. What was the bacteria? Garrett persisted. Something called Fusobacterium necrophorum. The identification of the bacteria told Garrett all he needed to know. The boy had Lemierre's disease.